feat(chat,seahorse): persist and display model_name across history (#2897)

* feat(chat,seahorse): persist and display model_name across history

* test(seahorse): fix lint regressions in repair coverage

* fix(pico): preserve model_name in live updates

* fix(pico): preserve model_name through live stream wrappers

web/frontend/src/api/sessions.ts

@@ -15,6 +15,7 @@ export interface SessionDetail {
     role: "user" | "assistant"
     content: string
     kind?: "normal" | "thought" | "tool_calls"
+    model_name?: string
     media?: string[]
     attachments?: {
       type?: "image" | "audio" | "video" | "file"

web/frontend/src/components/chat/assistant-message.tsx

@@ -33,6 +33,7 @@ interface AssistantMessageProps {
   content: string
   attachments?: ChatAttachment[]
   kind?: AssistantMessageKind
+  modelName?: string
   toolCalls?: ChatToolCall[]
   timestamp?: string | number
 }
@@ -41,6 +42,7 @@ export function AssistantMessage({
   content,
   attachments = [],
   kind = "normal",
+  modelName,
   toolCalls = [],
   timestamp = "",
 }: AssistantMessageProps) {
@@ -66,13 +68,20 @@ export function AssistantMessage({
   const copyMessageLabel = isCopied
     ? t("chat.copiedLabel")
     : t("chat.copyMessage")
+  const trimmedModelName = modelName?.trim() ?? ""
 
   return (
     <div className="group flex w-full flex-col gap-1.5">
       {!isCollapsedBlock && (
-        <div className="text-muted-foreground/60 flex items-center justify-between gap-2 px-1 text-xs opacity-70">
+          <div className="text-muted-foreground/60 flex items-center justify-between gap-2 px-1 text-xs opacity-70">
           <div className="flex items-center gap-2">
             <span>PicoClaw</span>
+            {trimmedModelName && (
+              <>
+                <span className="opacity-50">•</span>
+                <span>{trimmedModelName}</span>
+              </>
+            )}
             {formattedTimestamp && (
               <>
                 <span className="opacity-50">•</span>
@@ -104,6 +113,9 @@ export function AssistantMessage({
                   <IconTool className="size-3.5" />
                 )}
                 <span>{collapsedLabel}</span>
+                {trimmedModelName && (
+                  <span className="text-muted-foreground/45">{trimmedModelName}</span>
+                )}
               </div>
               <IconChevronDown
                 className={cn(

web/frontend/src/components/chat/chat-page.tsx

@@ -376,6 +376,7 @@ export function ChatPage() {
                     content={msg.content}
                     attachments={msg.attachments}
                     kind={msg.kind}
+                    modelName={msg.modelName}
                     toolCalls={msg.toolCalls}
                     timestamp={msg.timestamp}
                   />

web/frontend/src/features/chat/history.ts

@@ -50,6 +50,7 @@ export async function loadSessionMessages(
     role: message.role,
     content: message.content,
     kind: message.role === "assistant" ? (message.kind ?? "normal") : undefined,
+    modelName: message.model_name,
     toolCalls:
       message.role === "assistant"
         ? parseToolCallsValue(message.tool_calls)
@@ -86,7 +87,7 @@ function messageSignature(message: ChatMessage): string {
 
   return `${message.role}\u0000${message.content}\u0000${normalizeMessageTimestamp(
     message.timestamp,
-  )}\u0000${message.kind ?? ""}\u0000${attachmentSignature}\u0000${toolCallsSignature(
+  )}\u0000${message.kind ?? ""}\u0000${message.modelName ?? ""}\u0000${attachmentSignature}\u0000${toolCallsSignature(
     message.toolCalls,
   )}`
 }

web/frontend/src/features/chat/protocol.ts

@@ -83,6 +83,14 @@ function parseContextUsage(
   }
 }
 
+function parseModelName(payload: Record<string, unknown>): string | undefined {
+  if (typeof payload.model_name !== "string") {
+    return undefined
+  }
+  const modelName = payload.model_name.trim()
+  return modelName || undefined
+}
+
 export function handlePicoMessage(
   message: PicoMessage,
   expectedSessionId: string,
@@ -102,6 +110,7 @@ export function handlePicoMessage(
       const attachments = parseAttachments(payload)
       const contextUsage = parseContextUsage(payload)
       const isPlaceholder = payload.placeholder === true
+      const modelName = parseModelName(payload)
       const timestamp =
         message.timestamp !== undefined &&
         Number.isFinite(Number(message.timestamp))
@@ -116,6 +125,7 @@ export function handlePicoMessage(
             role: "assistant",
             content,
             kind,
+            ...(modelName ? { modelName } : {}),
             ...(toolCalls ? { toolCalls } : {}),
             attachments,
             timestamp,
@@ -135,6 +145,7 @@ export function handlePicoMessage(
       const messageId = payload.message_id as string
       const attachments = parseAttachments(payload)
       const contextUsage = parseContextUsage(payload)
+      const modelName = parseModelName(payload)
       const timestamp =
         message.timestamp !== undefined &&
         Number.isFinite(Number(message.timestamp))
@@ -160,6 +171,7 @@ export function handlePicoMessage(
               content,
               kind,
               toolCalls,
+              ...(modelName ? { modelName } : {}),
               ...(attachments ? { attachments } : {}),
             }
           })
@@ -178,6 +190,7 @@ export function handlePicoMessage(
               content,
               kind,
               toolCalls,
+              ...(modelName ? { modelName } : {}),
               ...(attachments ? { attachments } : {}),
               timestamp,
             },

web/frontend/src/store/chat.ts

@@ -44,6 +44,7 @@ export interface ChatMessage {
   content: string
   timestamp: number | string
   kind?: AssistantMessageKind
+  modelName?: string
   attachments?: ChatAttachment[]
   toolCalls?: ChatToolCall[]
 }